These constants can be used when working directly with Chinese characters.

These constants can be used in a variety of ways, but they can’t directly
distinguish between Chinese, Japanese, and Korean characters/words.
Chapter 12 of The Unicode Standard
(PDF)
has some useful information about this:

There is some concern that unifying the Han characters may lead to confusion because they are sometimes used differently by the various East Asian languages. Computationally, Han character unification presents no more difficulty than employing a single Latin character set that is used to write languages as different as English and French. Programmers do not expect the characters “c”, “h”, “a”, and “t” alone to tell us whether chat is a French word for cat or an English word meaning “informal talk.” Likewise, we depend on context to identify the American hood (of a car) with the British bonnet. Few computer users are confused by the fact that ASCII can also be used to represent such words as the Welsh word ynghyd, which are strange looking to English eyes. Although it would be convenient to identify words by language for programs such as spell-checkers, it is neither practical nor productive to encode a separate Latin character set for every language that uses it.

Some of the characters in this constant will not be Chinese characters,
but this is a convienient way to approach the issue. If you’d rather have
an enormous string of Chinese characters from a Chinese dictionary, check
out zhon.cedict.

A regular expression pattern for a Chinese sentence. A sentence is defined
as a series of CJK characters (as defined by
zhon.hanzi.characters) and non-stop punctuation marks followed
by a stop and zero or more container-closing punctuation marks (e.g.
apostrophe and brackets).

The string "·012345:-'". This contains all Pinyin marks that have
special meaning: a middle dot and numbers for indicating tone, a colon for
easily writing ü (‘u:’), a hyphen for connecting syllables within words,
and an apostrophe for separating a syllable beginning with a vowel from
the previous syllable in its word. All of these marks can be used within a
valid Pinyin word.

Validating and splitting Pinyin isn’t as simple as checking that only
valid characters exist or matching maximum-length valid syllables.
The regular expression library’s lookahead features are used in this
module’s regular expression patterns to ensure that only valid Pinyin
syllables are matched. The approach used to segment a string into valid
Pinyin syllables is roughly:

Match the longest possible valid syllable.

If that match is followed directly by a vowel, drop that match and try
again with the next longest possible valid syllable.

Additionally, lookahead assertions are used to ensure that hyphens and
apostrophes are only accepted when they are used correctly. This helps to
weed out non-Pinyin strings.

The string 'ㄅㄆㄇㄈㄉㄊㄋㄌㄍㄎㄏㄐㄑㄒㄓㄔㄕㄖㄗㄘㄙㄚㄛㄝㄜㄞㄟㄠㄡㄢㄣㄤㄥㄦㄧ'.
This contains all Zhuyin characters as defined by the Bomopofo Unicode
block. It does
not include the
Bomopofo Extended block
that defines characters used in non-standard dialects or minority
languages.

A string containing characters considered by CC-CEDICT to be Traditional Chinese characters.
Some of these characters are also present in
zhon.cedict.simplified because many characters were left
untouched by the simplification process.

A string containing characters considered by CC-CEDICT to be Simplified Chinese characters.
Some of these characters are also present in
zhon.cedict.traditional because many characters were left
untouched by the simplification process.